Serum miR-4530 sensitizes breast cancer to neoadjuvant chemotherapy by suppressing RUNX2

Xiao-Xiao Wang,1,* Fu-Gui Ye,2,* Jie Zhang,1,* Jun-Jing Li,1 Qing-Xia Chen,1 Pei-Yang Lin,1 Chuan-Gui Song1 1Department of Breast Surgery, Affiliated Union Hospital, Fujian Medical University, Fuzhou, People’s Republic of China; 2Department of Breast Surgery, Key Laboratory of Breast Cancer, Fudan University Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai, People’s Republic of China *These authors contributed equally to this work Purpose: Neoadjuvant chemotherapy (NAC) plays a pivotal role in the treatment of locally advanced breast cancer (LABC); however, breast cancer is a heterogeneous disease, individual responses to chemotherapy are highly variable. Therefore, the purpose of the current research is to identify biomarkers that can predict the chemotherapeutic response. Patients and methods: We recruited 78 patients with primary breast cancer who underwent taxane- and anthracycline-based NAC; these patients were divided into sensitive and resistant groups according to the Response Evaluation Criteria in Solid Tumors (RECIST) criteria. The microRNA microarray was conducted to explore differentially expressed miRNAs. Quantitative real-time polymerase chain reaction (qRT-PCR) further validated the relationship between miR-4530 and chemosensitivity in breast cancer patients. Results: No significant differences were observed between the two groups regarding the clinicopathological characteristics. miR-4530 showed the most potential involving breast cancer chemosensitivity. Mechanically, RUNX2 was identified one of the direct targets of miR-4530 and responsible for breast cancer chemosensitivity. Conclusion: Our results revealed that elevated serum miR-4530 levels may sensitize breast cancer to taxane- and anthracycline-based NAC by suppressing RUNX2; therefore, this miRNA has the potential to be a new biomarker for predicting breast cancer chemosensitivity. Keywords: miR-4530, serum, neoadjuvant chemotherapy, chemotherapeutic resistance, RUNX